In case of PC, FoundationOne CDx is an FDA-approved companion diagnostic used to detect P/LPVs in BRCA1, BRCA2, ATM, BARD1, BRIP1, CDK12, CHEK1, CHEK2, FANCL, PALB2, RAD51B, RAD51C, RAD51D, and RAD54L [36,37]. The gene discussed is RAD51C; the disease is pachyonychia congenita.